9

Specifications ......

Process Information

The following Table gives details of the process and test controls employed in the manufacture of the FX629

'Mil Std' Delta Codec.

Function

Reference

Remarks

Hermeticity

Fine Leak Test –

Mil Std 883C

using Method 1014 – test condition A1.

Coarse Leak Test –

Mil Std 883C

using Method 1014 – test condition C.

Burnin

Mil Std 883C

using Method 1015 – test condition E.

168 Hours @ 85

°C with 5v power, and clocks applied.

Temperature Cycling

Mil Std 883C

using Method 1010 – test condition B.

10 cycles -55

°C to +125°C.

The following mechanical assembly tests are Qualified to BS9450

Vibration

BS9450

Section 1.2.6.8.1

55Hz to 500Hz at 98 m/sec acceleration.

Shock

BS9450

Section 1.2.6.6

981 m/sec for 6 msec.

Low Pressure

BS9450

Section 1.2.6.12

Transport and Storage –

225mmHg (altitude 9000m).

Operation –

600mmHg (altitude 2400m).

Humidity

BS9450

Section 1.2.6.4

96 Hours @ 45

°C, 95% relative humidity plus condensed

water.

Notes: 1. Dynamic characteristics are specified at 5V unless otherwise specified.

2. All logic inputs except, Encoder and Decoder Data Clocks.

3. For an Encoder/Decoder combination, insertion loss contributed by a single component is half this

figure.

4. Driven with a source impedance of <100

Ω.

5. Recommended values – See Figures 5, 6, 7 and 8.

6 Group Delay Distortion for the full codec is relative to the delay with 820Hz, -20dB at the encoder input.

7. An Emitter Follower output stage.

8. 4.0V = 80% V

9. Analogue Voltage Levels used in this Data Sheet: 0dBm0 = 489mVrms = - 4dBm = 0dB.

-15dBm0 = 87mVrms. - 20dBm0 = 49mVrms = - 24dBm.

Application Recommendations

Due to the very low levels of signal and idle channel noise required in Military applications – a noisy or badly

regulated power supply could cause instability putting the overall system performance out of specification.

Adherence to the points noted below will assist in minimizing this problem.

(a)

Care should be taken on the design and layout of

the printed circuit board.

(b)

All external components (as recommended in

Figure 3) should be kept close to the package.

(c)

Tracks should be kept short, particularly the

Encoder Input capacitor and the V

(d)

Xtal/clock tracks should be kept well away from

analogue inputs and outputs.

(e)

Inputs and outputs should be screened wherever

possible.

(f)

A "ground plane" connected to V

eliminating external pick-up on the input and output

pins.

(g)

It is recommended that the power supply rails

have less than 1mVrms of noise allowed.

(h)

The source impedance to the Encoder Input pin

must be less than 100

Ω, Output Idle channel noise

levels will improve with even lower source impedances.